nltt_lines: Normalized version of the ape function ltt.lines.
Description
This is a modified version of the ape function ltt.lines:
add the normalized Lineage-Through-Time statistic of a phylogenetic tree
to an already existing plot
Usage
nltt_lines(phy, ...)
Arguments
phy
an object of class "phylo"
...
further graphical arguments that can be passed to lines()